Composition for treating ferrous metals



Patented Mar. 21, 1939 COMPOSITION FOR. TREATING FERROUS METALS Harley A. Montgomery, Highland Park, Mich.

No Drawing.

Application January 7, 1937,

Serial No. 119,525

6 Claims.

This invention relates to a metal coating composition and also to a method for using the same. More particularly, the invention relates to a composition combining unique qualities as an agent for the prevention of the rusting of ferrous metals, and an agent facilitating plastic deformations of the metals protected therewith.

In the past, it has been conventional practice inthe sheet mills and rolling mills to coat almost all of the ferrous materials sent out from the mills to prevent rust formation. For this purpose a variety of petroleum oils of varying viscosity, greases, waxes and so -called sloshing compounds has been used. The particular material utilized in a given instance has depended largely upon several factors, among which may be mentioned, the quality of the work,the degree of protection necessary, the estimated period of time before usage of the metal, the nature and finish of the metal, and also the cost of temporary rust proofing.

In plastic deformation operations, however, it has been conventional also to coat the surface of the metal, not to prevent the formation of rust,

but rather first to protect and lubricate the metal surfaces of the dies during the period of plastic deformation, secondly to lubricate the surface of the metal being deformed, and lastly to prevent galding pickups and scoring of the surfaces of all of the metals in pressure contact.

The rust proofing compounds of the types heretofore used have embodied qualities essentially different from those exhibited by the drawing compounds, and the former materials have neither been suited nor adapted to perform the functions of the latter. has become the accepted practice in the stamping plants, first to cleanse the metal received from the sheet mills so asto remove the antirust coating, if one has been applied, then recoat or retreat the sheets with one of the lubricative 'drawing compounds. It is obvious that the duplication of effort is not only expensive but also wasteful, time consuming and inefiicient.

It has been the object of the present invention to combine in a simple, single composition, the qualities and capacities which enable the substance first to .function efiiciently as insulation, preventing the formulation of rust on the surfaces of ferrous metals (during storage), "and secondly, as a lubricant assisting plastic deformation of the metal which it has protected against the formation of rust during the storage period.

The objective of the invention, in other words, has been to provide a coating composition having qualities which enable the substance to function efilciently, in sequence, first as a rust proofing agent for ferrous metals, then as a drawing com pound. It will be understood, of course, that For these reasons, it

almost any greasy substance at once embodies a lubricative as well as rust proofing material, in the broadest.indicative sense in which these terms might be used. From the point of view of practical industry, however, one appreciable 5 problem exists in providing in a composition the qualities which enable the composition to compare more than favorably with the individual materials formulated particularly to suit the requirements of the several respective uses "conjointly to which the composition of the present invention is directed.

The sheet mills frequently do not know the nature of theuses nor the degree of plastic deformation to which the sheets which they are 1 shipping, will be subjected. If the degree of plastic deformation be small, then little or no drawing compound might be required, whereas, if the degree of deformation be large, then to suit the requirements the composition adapted to be applied at the mills, for rust proofing during storage, and for lubrication of the sheets at the fabricating plant during plastic deformation, must embody drawing compound qualities of the highest value. It is in these respect that the terms rust proofing, and drawing lubricant" are used herein to denote qualities of a single substance, possessed of the capacity to function efficiently for both purposes.

Broadly speaking, the composition of the present invention comprises the combination of fatty acid of an organic oil in a mineral oil, which if desired is reduced in viscosity with a second mineral oil of lighter viscosity, or with a mineral oil diluent such as kerosene. The discovery upon which the invention is predicated is paradoxical. The common concept has been that fatty acids of organic oils are corrosive, particularly, in respect to ferrous metals in that they tend to react with the metals to produce corresponding metallic soaps. The peculiarity resides in the determination that these same fatty acids, when incorporated in mineral oil vehicle, not only fail to react deleteriously in the manner expected, but

actually contribute first to the capacity of the oil to prevent rust on metal, as well as provide secondly, in the resulting composition, qualities which enable it to function efiiciently as a lubricant in the plastic deformation of metals as great as 14 gauge in thickness.

According to the present invention, my composition differs from conventional rust proofing materials in several important respects. An ingredient known to have corrosive tendencies, in respect to ferrous metal deliberately is added to mineral oil vehicle to provide a composition which protectsferrous metal efilciently and reliably against corrosion and rust. Secondly, the coating which is applied, whetherit be treated as a rust proofing coating, or as a drawing lubricated o 1 I coating, is superior to the conventional individual materials used for these several purposes in the past. In providing the double function in a given composition in the manner describedan improvement is imparted to each of the several functions, and in this manner the sheet mills are enabled to coat their sheets with assurances that the metals will be protected during shipment .and storage, while the fabricating plants may proceed with the fabrication operations with assurance that the sheets, dies and metals in pressure contact will be protected during all of the plastic operations, except those of the most unusual variety where extremely great film strength is required. The economic advantages attendant the elimination of the rust proofing removal operation, and the elimination of the drawing lubricant frecoating operation, are apparent.

In accordance with the present invention an appreciable quantity of fatty acid of an organic .oil is incorporated in mineral oil. By reason of the importance of the cost factor, the present invention is disclosed in relation to the use of the fatty acid of degras, as the fatty acid best suited to the purpose. However, I have determined that the fatty acid purposely established in the oil may comprise the fatty acid of palm oil, lard oil, vegetable oil, fish oil, oleic acid and similar acids of fat origin and like nature.

The oil vehicle in which the fatty acid is established preferably comprises ordinary mineral oil having a Stormer viscosity of 100@ 100 C. If the oil is too thick (the addition of fatty acid tends to thicken it further) then the material is difficult to apply properly. On the other hand, if the final composition is too thin in consistency, then the loss and waste, through drainage from the sheets, is appreciable.

The following formula is provided as an example of one composition formulated in accordance with the present invention and well suited to use in the treatment of ordinary cold or hot rolled sheet steel intended for use in the fabrication of metal articles such as auto bodies, stamp-' lugs and fenders, engine oil pans, etc.

Per cent by weight Fatty acid of degras about 20 Mineral oil, viscosity 100@ 100 about 20 Kerosene oil about 60 The kerosene oil, inapproxlmately the quantity disclosed, lowers the viscosity of the composition to the pointof greatest ease of application and best results. Instead of kerosene, such substances as furnace oil, gas oil, heavy naphtha, andthe like maybe used.

In formulations of the compositions responsive to the concept of the present invention, I prefer to use approximately equal parts of fatty acid and mineral oil. However, depending upon the particular ingredients selected and the uses to which the final product is to be put, the fatty acid content may vary from approximately 5% to 20% based on'the weight of the oil.

The evidence available from microscopic examination oi. the surfaces of ferrous metals coated with compositions of the present invention, tends to explain, at least in part, the-reasons which account for the peculiar improvement in results. In the first place, mineral oils containing fatty acid of organic origin tend to exhibit extremely low surface tension. During storage, which usually is a period of from two to three days to a week or more, the composition coating wets thoroughly the surface of the metal, and in this respect is distinguished from the superficial film exhibited by conventional rust proofing (and even the drawing lubricant) coatings of the past. 'Moreover, the molecular flow of the metal, in respect to the operation of plastic deformation, is improved materially by reason of the close association and bonding of the coating to the metal. The metal is protected thoroughly against rusting during the time that it is being prepared for the operation subsequent to storage. It will be understood that the foregoing explanation is attempted only to account for the reasons leading to the present advance in an art already crowded and complex. The invention in substance, therefore, comprehends a sheet of ferrous metal insulated protectively against rusting prior to and during storage, and lubricated protectively during plastic deformation, subsequent to storage, by a composition containing fatty acid of organic oil origin purposely established in mineral oil vehicle of appropriate viscosity.

After plastic deformation or working of the metal has been completed, the metal is cleaned and prepared for finishing by treatment thereof in the conventional manner, either with a solvent cleaner such as naphtha, gasoline, benzine or synthetic solvent, or by, treatment with an aqueous alkaline solution.

Having described my invention, I claim:

1. A ferrous metal article having a surface insulated with a composition adapted to protect the metal against rusting during storage, and to .lubricate the metal during plastic deformation thereof, subsequent to storage, which insulating coating comprises the fatty acids of degras, min eral oil and'kerosene.

2. A sheet of ferrous metal insulated against rusting during storage and lubricated for plastic deformation, subsequent to storage, with a coating comprised of the fatty acids of degras in mineral oil, and a lubricative diluent such as kerosene.

3. A composition adapted to be applied to ferrous metal to protect the same against rusting during storage and lubricate the same during plastic deformation, consisting of the fatty acids of degras in a lubricative medium such as mineral oil.

4. A new composition of matter comprising a homogeneous admixture of fatty acids of degras, I

mineral oil and kerosene.

5. A process of treating ferrous metal during storage and during plastic deformation of the metal, which process consists in applying a homogeneous admixture of fatty acids of degras and mineral oil, then storing the metal until it is thoroughly wetted by the admixture, and then subjecting the metal to plastic deformation.

6. A sheet of ferrous metal having a surface insulated with a composition which protects the surface against rusting during storage and which lubricates the metal during plastic deformation subsequent to storage, which insulating composition comprises a homogeneous admixture of approximately equal parts by' weight of fatty acids of de'gras and mineral oil.

HARLEY A. MONTGOMERY. 

